August 3, 2020

Household Transmission of SARS-CoV-2 a Systematic Review and Meta-Analysis of Secondary Attack Rate

Category: Article Summary

Topic: Transmission

• [Preprint, not peer-reviewed] Madewell et al. performed a meta-analysis of 40 studies of SARS-CoV-2 household secondary attack rate (SAR). Overall, the estimated mean SAR for household contacts was 19% (95%CI 15%–23%) and family contacts was 18% (13%–35%), both with significant heterogeneity. SARs were significantly higher from symptomatic index cases than asymptomatic index cases (20% vs. 1%), to adult contacts than to child contacts (31% vs. 16%), to spouses than other family contacts (43% vs. 18%), and in households with one contact than in households with three or more contacts (45% vs. 25%), though the authors note that the analysis does not adjust for hosuehold crowding. [Editorial note: This analysis did not have strict temporal criteria for the identification of a case relative to other cases in the household, which may inflate the estimated SARs.]  

Madewell et al. (Aug 1, 2020). Household Transmission of SARS-CoV-2 a Systematic Review and Meta-Analysis of Secondary Attack Rate. Pre-print downloaded Aug 3 from https://doi.org/10.1101/2020.07.29.20164590